This invention relates generally to electronic gaming machines interconnected by a computer network and more particularly to a method for varying and awarding bonuses to gaming machines over a gaming network.
Casinos typically include electronic gaming machines (EGMs) such as slot machines and video poker machines. Slot machines, for example, usually include three reels that each have a plurality of symbols printed thereon. After the player applies a wager to the machine, he or she starts play by triggering a switch that starts the reels spinning. Each reel stops at a random position and thereby presents three symbols--one from each reel. Some combinations of symbols do not pay any jackpot. Others pay varying amounts according to predetermined combinations that appear in a pay table displayed on the machine and stored in the gaming machine's programmable read-on memory (PROM).
More recently, multiple gaming machines have been linked together into groups of machines that share the same bonus pool. A simple example of such a system is progressive video poker in which players play the primary poker game on one of a plurality of gaming machines grouped together on the casino floor. A coin in counter, linked to all machines sharing the progressive pool, counts the total amount of money played in the group of machines and advances the progressive bonus pool accordingly. For instance, the casino can choose to set aside 5% of all money played on the group of video poker machines to the bonus pool. The amount of the pool is displayed on a large LED display and is incremented as money is played. This amount is awarded automatically as a bonus should a player on one of the video poker machines receive a designated winning hand such as a royal flush. After the bonus is awarded, the bonus pool is seeded with a nominal amount that is further incremented as described above.
The advantage of the progressive system is that the bonus pools from individual machines can be pooled to form larger awards which in turn attracts more players. When taken to the extreme, progressive bonuses can be pooled together not only from machines in different areas of the casino, but from different casinos in different states. More complex examples for bonusing are implemented using bonus servers over a network, such as disclosed in co-pending application Ser. No. 08/843,411, filed Apr. 15, 1997 and assigned to the Assignee of the present application (the '411 application), which is incorporated herein by reference for all purposes. Also incorporated herein by reference for all purposes is U.S. Pat. No. 5,655,961, assigned to the Assignee of the present application (the '961 patent), which also discloses bonuses that can be implemented by bonus servers over a network.
Bonusing on gaming machines also occurs for fixed amounts during all times on which the gaming machine is played. The pay table represented in FIG. 6 shows such a bonus. Referring to the top of the pay table in FIG. 6, the top jackpot award (shown as a pot on each reel) pays two thousand for a one coin bet, four thousand for a two coin bet and ten thousand for a three coin bet. The fixed bonus then, operative during all pulls of the gaming machine, yields an extra four thousand coins over and above the expected six thousand coin jackpot for a three coin bet. Such a system would not act to increase short-term gameplay since the bonus would always be active, and would either increase (as in the case of progressive jackpots) or stay fixed (as dictated by the pay table). In the case of progressive jackpots, in fact, it might hinder short term game play since the player might wait to play the game until the progressive jackpot rises over a certain amount.
Accordingly, a need remains for an bonusing system which increases play at gaming machines coupled over a network.